Waste fluid in hydrocarbon fluid production systems, such as used fracturing fluid, often contains trace amounts of hydrocarbons, such as oil. The recovery of such hydrocarbons may occur, typically, at great cost and energy usage. For example, gun barrel tanks, or settling tanks, may be used for separating oil and non-hydrocarbons by gravity segregation forces. In some aspects, oil at the top of the tank may be skimmed off, however, such oil often contains an unacceptable amount of water and non-hydrocarbons. Further, heating and pumping systems used in gun barrel tanks may further separate the oil and non-hydrocarbons through the addition of great amounts of heat (and thus energy) to the liquids in the tank. Still, the remaining oil in the tank, even after heat separation, may contain an unacceptable amount of water.